Gargantia on the Verdurous Planet
Castaway
S1 E1:
Ensign Ledo is a Machine Caliber pilot in the Galactic Alliance of Humankind, fighting a seemingly endless war against the Hideauze out in the far reaches of the galaxy. But after an accident during the latest battle he and his Machine Caliber, Chamber end up on a mysterious planet populated with a seemingly primitive tribe of humans.